Rock drilling apparatus



April 19, 195 A. FEUCHT ETAL 3,246,706

ROCK DRILLING APPARATUS Filed Oct. 18, 1965 5 Sheets-Sheet l FIGZ INVENTOR ALBERT FEUCH DAVID L. THOMAS BY ATTORNEYS April 19, 1966 A. FEUCHT ETAIL ROCK DRILLING APPARATUS 5 Sheets-Sheet 2 Filed Oct. 18, 1963 FIG?) INVENTOR. ALBERT FEUCHT BXDKAVID L.THOMAS m'rosznevs April 19, 1966 A. FEUCHT ETAL ROCK DRILLING APPARATUS 5 Sheets-Sheet 5 Filed Oct. 18, 1963 INVENTOR.

United States Patent 3,246,706 RGCK DRILLENG APPARATUS Albert Feucht, Sidney, and David L. lihomas, Columbus, Ohio, assignors, by direct and mesne assignments, to Westinghouse Air Brake Company, Wilmer-ding, Pa., a corporation of Pennsylvania Filed Get. 13, 1963, Ser. No. 317,277 8 Claims. ((31. 173-147) The present invention relates generally to improvements in rock drilling apparatus, and relates more particularly to the provision of an improved feed mechanism and supporting structure for pneumatically or hydraulically actuated rock drills intended for either stoper or horizontal drilling.

A primary object of the invention is to provide a rock drill with an improved balanced feed leg embodying a simple, highly flexible and effective torque resisting S111 port and novel and efficient drill advancing and guiding mechanism.

In the drilling of rock and ore, it is customary practice to support the drill for advancement to and retraction from the work by means of feed mechanism which includes a feed cylinder having a power actuated piston slidable therein and connected to the drill. Such drill supports are commonly called feed legs, and it is always desirable to provide for utmost stability and maximum feed of the drilling motor toward and into the work. In United States Patent No. 2,819,042, dated January 7, 1958, to J. E. Feucht, a rock drilling apparatus is disclosed which is provided with a power cylinder type feed leg arranged and constructed so that the maximum feed of the drilling motor is materially greater than that of the feed cylinder thereby enabling use of a feed mechanism of short overall length capable of a relatively long feed. While the feed arrangement shown and described in this prior patent has enjoyed a high degree of com mereial acceptance and success when used in conjunction with purely percussive type rock drills, such prior apparatus still left something to be desired with regard to balance and stability, and its use has moreover been unduly restricted primarily due to its single point support.

Furthermore, in drilling operations wherein the drill steel is rotated, regardless of whether or not the rotation is accompanied by percussive action, a torque is imposed on the drilling machine during operation, and provision must therefore be made to anchor the apparatus in order to prevent it from rotating by reason of such torque. For this purpose, it has been heretofore proposed to provide the feed leg or drill support with a foot which has laterally spaced apart ground engaging points, and such prior structures are exemplified in United States Patents No. 444,122, dated January 6, 1891, No. 1,783,290, dated December 2, 1930 and No. 1,860,946, dated May 31, 1932. However, while the feet of the prior assemblages disclosed in these patents were effective to prevent rotation imposed on the drill during operation, they permitted tilting of the drilling machine only about an axis or fulcrum defined by a line lying on the two laterally spaced hearing points, and universal tilting movement of the drill in any desired direction while maintaining proper balance of the drilling machine in all of its positions was not possible in the prior devices.

It is therefore an additional object of this invention to provide an improved rock drilling apparatus which obviates all of the aforesaid disadvantages and objections of prior devices.

Another object of the invention is to provide an improved feed leg and support particularly adapted for rotary and for rotary-percussion type drilling machines which effectively resists the rotation tendency created by the torque imposed on the machine during operation while 3,246,706 Patented Apr. 19, 1966 also permitting universal tilting movement and angular positioning of the drill.

Still another object of this invention is to provide an improved drill supporting feed leg for fluid actuated rock drills which permits immediate universal adjustment of the drilling machine to any desired angular operative position while always maintaining the load along the centerline of the drill steel.

An additional object of the present invention is to provide an improved balanced feed leg for rock drills which embodies a pair of laterally spaced power cylinders and elongated flexible elements coupling the feed pistons of each cylinder to the drill in a manner whereby the distance of drill travel is always double that of the feed cylinder travel.

These and other objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the several features constituting the present invention and of the mode of constructing and operating a typical fluid actuated rotary or rotarypercuss-ion drill embodying the improvements may be had by referring to the drawings accompanying and forming a part of this specification, wherein like reference characters designate the same or similar parts in the various views.

FIG. 1 is a side elevational view of a typical rock drilling apparatus embodying the invention;

FIG. 2 is a vertical transverse section through the device taken along the line 22 of FIG. 1;

FIG. 3 is a fragmentary end view of the device with the drill steel and one of the power cylinders and attendant mechanism shown in transverse section;

FIG. 4 is a transverse horizontal section through the feed leg taken generally along the line 4-4 of FIG. 2

1 but with parts of the supporting foot and its connection to the leg being additionally broken away and shown in section;

FIG. 5 is a somewhat enlarged fragmentary view of the lower end of the feed leg and the supporting foot taken from the same side of the device as in FIG. 1 and illustrating the feed leg in different angular positions;

FIG. 6 is a similarly enlarged fragmentary view of the lower end of the feed leg and supporting foot taken from the right side of FIG. 1 and again illustrating the feed leg in diiferent angular positions; and

FIG. 7 is a transverse section through the upper end of the feed leg cylinders along the line 77 of FIG. 1; and

FIG. 8 is a similar section through the lower end of the feed leg cylinders taken along the line 8-8 of FIG. 2.

While the improvements have been illustrated and de scribed as being especially advantageously embodied in a rock drill of the stoper type actuated by fiuid pressure and utilizing a particular type of bit, it is not intended to thereby unnecessarily limit or restrict the invention since the improved feed leg, supporting foot and stabilizing mechanism may be used to like advantage in connection with drills driven by gasoline engine or electric motor and employing drill bits of any type. It is also contemplated that certain descriptive terminology used herein shall be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, the reference numeral 10 designates generally a rotary or rotary-percussion rock drill, and the reference numeral 12 designates generally the supporting and feeding mechanism for the drill. The drill motor 13 may be actuated in any suitable manner as by means of hydraulic or pneumatic fluid or the like supplied through lines 11, 11' to rotate the drill steel 14 and bit 15 either with or without percussive action. As shown in United States Patents No. 1,538,421 dated May 3 l9, 1925'to Clark, No. 1,575,987 dated March 9, 1926 to Gilman and numerous other patents, such drilling devices are old and well-known, and since the rock drill structure as such does not form a part of the present invention, a detailed description of the same is believed unnecessary.

In accordance with the invention, the drill motor 13 is supported for axial movement by the feed leg 12, the frame of which consists generally of a pair of laterally spaced parallel feed cylinders 17 bracketed together as by upper and lower cross-members 18, 19 respectively to provide a rigid assembly. To guide the drill in its movement, the motor housing 13 is formed with a pair of lugs or projections 20 extending laterally from opposite sides thereof and slidably receivable in laterally open outer guidcways 21 formed in the adjacent sides of the cylinders 17 along the length thereof (FIGS. 3 and 4).

The power pistons 23 are double acting and are simultaneously actuated by means of fluid under pressure conducted to the displacement chambers 24 selectively above or below the confined heads 25 of the pistons via upper and lower feed line 26, 26' respectively. The extension and retraction of the pistons is accomplished under the control of an operator, and the outwardly projecting ends of the pistons 23 are bracketed by an articulatable foot 27 hereinafter more fully described. The drill 10 is, in turn, connected to the foot 27, which joins the extending ends of the power pistons, as by means of one or more chains 29 shown herein as two in number and each of which is attached at one end to a side clamp 30 carried by the motor 13 and at the other end to a laterally extending lug 42 on the foot 27 as by means of a relatively long tie rod 31 or the like, the chain 29 in each case being routed over hoist sheaves 32, 33 rotatably supported by the feed leg.

This structure is tantamount to a telescopic feed, and the feed cylinders 17 will move one unit of length in relation to the feed cylinder pistons 23 as fluid under pressure is admitted to the chambers 24, while the drill 10 is simultaneously moved another unit of length in relation to the feed cylinders by means of the chains 29. Accordingly, the total distance of drill travel is always double that of the cylinder travel with the arrangement thus disclosed, and a feed mechanism of short overall length yet capable of a relatively long feed is provided.

To prevent chain kinking and/or possible jamming of the drill motor 13 in its movement, the drilling apparatus is additionally provided with a novel closed circuit cable arrangement which cooperates with the guiding and feed ing means to stabilize the drill. This closed circuit system comprises generally a pair of cables 35 each of which is attached at 36 to the drill motor 13 adjacent to one of the side chain clamps 30 and each of which is then routed over a pair of cable sheaves 37, 38 and attached at the opposite end thereof to the hoist chain 29 on the other side of the drill motor as at the upper end 39 of the tie rod 31. By thus crossing these cables 35 over from the left side of the drill motor 13 to the right side hoist chain 29 and vice versa, additional stability is gained and the possibility of cocking and resulting jamming of the drill during its movement is minimized.

The articulatable foot 27 is extremely important since it permits the drill to be supported in any desired angular position while also being so constructed as to resist the torque created by the drill in its operation. This stabilizing foot 27 is shown herein as being in the form of a ring pivotally mounted as by pins 41 on a pair of laterally projecting lugs or arms 42 carried by the extending ends of the pistons 23, the pivot pins 41 being thus laterally offset from the axis of the feed cylinders 18 and being located in a plane common to that of the drill motor and bit axis. At equal distances on opposite sides of its pivot axis, the ring member 27 is provided with depending pointed abutments 43 for engaging the ground to support the drill, and the entire assemblage is accordingly swingable about these pointed supports 43 to any desired angular position as shown in FIG. 5 while also being swingable about the pivot axis provided by the pins 41 as shown in FIG. 6. The spaced prongs or ground engaging points 43 therefore provide a support for the drilling apparatus and feed leg which anchors the assemblage against the torque created by rotation of the drill during operation, and universal movement of the drill assembly to any angular position is moreover provided while the support for the load applied to the drill is always maintained on the center-line of the drill steel and bit.

To facilitate manipulation of the apparatus while aiding in more rigidly coupling the cylinders 1'7 together, a head bracket and cover member 45 is rigidly secured to the upper crossmember 18 in a suitable manner, and a manipulating handle 46 is secured to the member 45. The chains 29 and sheaves 32, 33 are accordingly protectively housed, and the drill may be manipulated conveniently by means of the gripping handle. As shown, the lower ends of the tie rods 31 may be conveniently secured to the respective pistons 23 by extending the lugs 42 to opposite sides of their carrying pistons, and the sheaves 37, 38 may be suitably rotatably supported on the lower crossmember 19.

Since the feed leg cylinders are double-acting, the feed mechanism is capable of powered retraction as well as powered extension; and as shown in FIGS. 7 and 8 both of the feed legs may be fed by common hoses or tubes 26, 26. Also, since the annular area between the rod 23 and the cylinder wall of each piston cylinder unit is small compared to the piston rod area at the end of the piston heads 25, retraction is more rapid than extension. It is also believed apparent from the foregoing description that the retraction forces are communicated to the various elements of the feed leg by the cables 35. Thus, in addition to preventing cocking of the drill motor and possible connecting or jamming of the chains the cables also accomplish retraction.

The primary function of the upper and lower feed leg cylinder cross member or braces 18, 19 is to hold and retain the two cylinders 17 parallel and to maintain their axial relation to each other while resisting the twisting forces due to torque imposed on the feed leg during either bolt tightening or drilling. However, as is apparent from the foregoing detailed description, at secondary function of the lower cross member 19 is to provide support for the cable sheaves 37, 38.

The improved feed leg mechanism and supporting structure for the drill enables high thrust and torque forces to be transmitted to the drill steel without inducing any bending moments in the drill steel and without requiring any external stabilizing forces, and it is desirable that the lower abutments 43 of the supporting foot lie in a plane which contains the center line of the drill steel. It is also desirable, although not necessary, that the center lines of the chains 29 be located equidistant from and lie in a plane containing the center line of the adjacent cylinder, and if this condition is satisfied, the feed leg cylinders will encounter no bending moments due to the thrust loadings developed by hydraulic pressure acting on the piston rods. It is also desirable that the center lines of the two chains connected to the drill motor be equidistant from and lie in a plane containing the center line of the drill steel, and if this condition is satisfied, the drill steel will encountered no bending moments.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

We claim:

1. Drilling apparatus comprising, a power feed cylinder, a piston in said cylinder having a rod portion extend ing from one end thereof, means for admitting pressure fluid to said cylinder to effect axial movement of said cylinder relative to said piston, a drill motor having its drilling axis lying in a plane laterally offset from and substantially parallel to said piston rod and the plane of movement of said cylinder, means for advancing said motor as axial movement of said cylinder is effected, a lug projecting laterally from said piston rod beyond said drill motor and intersecting the plane of the drill axis thereof, and a supporting foot pivotally secured to said lug with its pivot axis lying in the plane of the drilling axis and extending transversely of said lug, said supporting foot having a pair of ground engaging abutments spaced on opposite sides of its pivot axis, one of said abutments being located in the plane of movement of said cylinder and the other of said abutments being located a corresponding distance outwardly beyond the opposite side of said pivot axis.

2. Drilling apparatus comprising, a pair of laterally spaced power feed cylinders bracketed together to form a unitary structure, a piston in each of said cylinders and each having an extending rod portion, means for admitting pressure fluid to each of said cylinders to effect axial movement of said bracketed cylinders relative to said pistons, a drill motor having its drilling axis lying in a plane laterally ofiset from and substantially parallel to said piston rods and the plane of movement of said bracketed cylinders, means for advancing said motor as axial movement of said cylinders is eifected, a lug projecting laterally from each of said piston rods beyond said drill motor and the plane of the drilling axis thereof, and a supporting foot pivotally secured to and lying between said lugs with its pivot axis intersecting the plane of the drilling axis and extending transversely of said lugs, said supporting foot having a pair of ground engaging abutments spaced on opposite sides of its pivot axis, one of said abutments being located in the plane of movement of said cylinders and the other of said abutments being located a corresponding distance outwardly beyond the opposite Side of said pivot axis.

3. Drilling apparatus according to claim 2, wherein the means for advancing the motor includes guide means between the drill motor and the power cylinders permitting relative movement between said motor and said cylinders and at least one chain secured at one end to the drill motor and at the other end to the piston rods and medially traversing a sheave carried by the cylinders.

4. Drilling apparatus according to claim 3, wherein a pair of cables is provided for stabilizing the drill motor in its movement, said cables each being connected at one end to said motor on one side of the drilling axis and at the other end to the piston rods on the opposite side of the drilling axis and each cable medially travers ing roller guide means carried by the power cylinders.

5. Drilling apparatus according to claim 2, wherein the means for advancing the motor includes guide means between the drill motor and the power cylinder permitting relative movement between said motor and said cylinder and a pair of chains each secured at one end to said motor on one side of the drilling axis and at the other end to the piston rod on the corresponding side of the drilling axis, and each of said chains also medially traversing roller guide means carried by the cylinder on the corresponding side of the drilling axis.

6. Drilling apparatus according to claim 5, wherein a pair of cables is additionally provided for stabilizing the drill motor in its movement, and in which two pairs of spaced sheaves are mounted on the bracketed cylinder assembly, said cables each being connected at one end to said motor on one side of the drilling axis and at the other end to the piston rod on the opposite side of the drilling axis and each cable medially traversing one of said pairs of sheaves.

7. Drilling apparatus comprising, a pair of laterally spaced power feed cylinders bracketed together to form a unitary structure, a piston in each of said cylinders and each having an extending rod portion, means for admitting pressure fluid to each of said cylinders to effect axial movement of said bracketed cylinders relative to said pistons, a drill motor having its drilling axis lying in a plane laterally off set from and substantially parallel to said piston rods and the plane of movement of said bracketed cylinders, means for advancing said motor as axial movement of said cylinders is effected, a ground engaging supporting foot for said cylinders, two pairs of spaced sheaves mounted on the bracketed cylinder assembly, and a pair of cables for stabilizing said drill motor in its movement, said cables each being connected at one end to said motor on one side of the drilling axis and at the other end to the piston rod on the other side of the drilling axis with each cable medially traversing one of said pairs of sheaves.

8. Drilling apparatus according to claim -7, wherein the means for advancing the motor includes a pair of chains each secured at one end to the motor on one side of the drilling axis and at the other end to the piston rod on the corresponding side of the drilling axis, each of said chains medially traversing roller guide means carried by the cylinder on the corresponding side of the drilling axis.

References Cited by the Examiner UNITED STATES PATENTS 1,543,883 6/1925 Slater 173-34 2,168,541 8/1939 Slater l7336 2,787,250 4/1957 Feucht et al. l73l47 2,788,194 4/1957 Hale l73l47 2,819,042 1/1958 Feucht l7336 2,905,442 9/1959 OFarrell l7336 BROUGHTON G. DURHAM, Primary Examiner.

D. FAULCONER, L. P. KESSLER, Assistant Examiners. 

1. DRILLING APPARATUS COMPRISING, A POWER FEED CYLINDER, A PISTON IN SAID CYLINDER HAVING A ROD PORTION EXTENDING FROM ONE END THEREOF, MEANS FOR ADMITTING PRESSURE FLUID TO SAID CYLINDER TO EFFECT AXIAL MOVEMENT OF SAID CYLINDER RELATIVE TO SAID PISTON, A DRILL MOTOR HAVING ITS DRILLING AXIS LYING IN A PLANE LATERALLY OFFSET FROM AND SUBSTANTIALLY PARALLEL TO SAID PISTON ROD AND THE PLANE OF MOVEMENT OF SAID CYLINDER, MEANS FOR ADVANCING SAID MOTOR AS AXIAL MOVEMENT OF SAID CYLINDER IS EFFECTED, A LUG PROJECTING LATERALLY FROM SAID PISTON ROD BEYOND SAID DRILL MOTOR AND INTERSECTING THE PLANE OF THE DRILL AXIS THEREOF, AND A SUPPORTING FOOT PIVOTALLY SECURED TO SAID LUG WITH ITS PIVOT AXIS LYING IN THE PLANE OF THE DRILLING AXIS AND EXTENDING TRANSVERSELY OF SAID LUG, SAID SUPPORT- 